Channeled monoliths for selective recovery of a lacto-tripeptide from a crude hydrolyzate

Adsorption processes using a packed bed reactor are often used for the purification of nutraceuticals. However, when dealing with untreated streams, this leads to fouling and consequent increase in pressure drop. This work compares the use of channeled monoliths, "honeycomb" structures, with a packed bed, both made of the same type of activated carbon. The intrinsic permeability and performance of both structures during the adsorption of a bioactive peptide from a crude hydrolyzate were studied. Breakthrough experiments were performed on both types of systems under similar conditions. The results showed similar productivity and dynamic adsorptive capacity for both structures at comparable linear velocity and residence time, but the packed bed showed a strong pressure drop increase during column saturation, revealing plugging of the column, especially at high velocities (short residence times). The channeled monoliths did not present any significant pressure drop increase, and were able to operate at high velocities which increase the range of application for these types of processes

Exergy efficiency from staple food ingredients to body metabolism : The case of carbohydrates

One of the methods to evaluate the efficiency in the production of foods is using exergy, the share of useful energy, and exergy analysis. In this paper, we propose a link between exergy analysis and nutrition to account for the exergy efficiency (exergy of output per exergy of input) in the metabolism of nutrients from foods in the human body. For this, we analyzed the exergy efficiency of four different chains of carbohydrate-rich products based on semi-industrial preparation processes and we included nutrient bioavailability through the use of several bioavailability indicators, including the glycemic index and protein digestibility. The least exergy efficient chain changed when not only looking at the exergy losses of the food processing chains, but also including the bioavailability and conversion of nutrients into adenosine triphosphate (ATP), the main molecule for energy storage in the body. When including only the processing chain, white bread presented the highest exergy loss, whereas the lowest values pointed to the spaghetti chain when also including metabolism both because of its preprocessing chain and its low bioavailability. In contrast, cooked potatoes were found to be an efficient source of ATP due to both a high metabolic efficiency and low process exergy losses. The carbohydrate bioavailability had a strong influence on the overall exergy efficiency of the studied cases, which shows the importance of including bioavailability aspects in the sustainability assessment of industrial food processing chains